/v2/sessiontoken - it is a part of URL i.e. it will be appended to value of host header which is provided in 2nd line. So whole URL will form like http://app.kashflow.com/v2/sessiontoken

HTTP/1.1 - This request is created using HTTP/1.1 version of sign/code language. It's modern. It might contain modern slangs ;-)

From 2nd line starts all request headers and their values follow after colon sign i.e. `:`. Each header has a different meaning and the other party understands it's value accordingly.

Host- request will go to this server address. Address of the server for which this message is intended. Client is saying "Hey Mister! I'm talking to you"

Content-Type - It is a message for the server that the body of this request that follows (last line), is in JSON format. If you want to interpret it please make a note about this. Client says "I'm talking in Spanish. Use interpreter accordingly ;-)"

Accept - means "As a client I will only understand if you return me a response body which is in JSON format (Spanish language)"

After an extra line break comes body of the request. That is actual talk/speech of client to server.

So this is what client has told to the server. Now server gets the request. It understands/interprets/decodes the request. It processes i.e. takes action as per the request. (In this case, client expects the server to verify the username and password, create an authentication token and respond with the same if username and password are valid. This part is creation/invention of a developer's mind. You as a developer will decide what you want the client to request and program the server to do as per the request.) Finally server informs back (HTTP Response) to the requester (client) about what action it took.

Look at HTTP status codes to decode this response.3. Browser is an HTTP client.
So let's understand how browser talks HTTP.

Fire up chrome

Hit F12 key to open up chrome dev tools.

Select network tab on chrome dev tools

Tick "Preserve log" checkbox

Type google.com in address bar (in chrome main window)

Hit enter.

Select the first request from the list in chrome dev tools window.

This is what I get to see. Let's decode it.

HTTP Request

GET request to `/` (it's a forward slash) i.e. root of the host google.com using HTTP 1.1 version of language

Browser `Accept`s or understands only one of these "text/html, application/xhtml+xml, application/xml" other certain image formats etc

HTTP Response

302 Found . It means server is saying that "You have reached at correct address and with valid parcel (request), unfortunately, the information (resource) you are looking for has moved to other place (specified in location header)"

Look at the 2nd request in the list (chrome dev tools). Is it a request to same URL which is specified in location header? Yes it is. Browser has interpreted the response correctly and requested other URL as per the response it got from the server.

Thanks for sharing such wonderful information about Web Development Tool.I read your articles very excellent and the i agree our all points because all is very good information provided this through in the post.